The continuing depletion of fossil and nuclear fuels may be one of the most significant long term problems facing the world. There is considerable disagreement regarding the size of the depletable fossil and nuclear fuel resources. Thus, increasing interest is now centered about renewable energy resources such as solar energy.
The collection and concentration of solar energy for utilization in solar furnaces is well known in the art. Until relatively recently such solar furnaces were for the most part adapted for the heating of a fluid, generally a liquid such as water, for the production of steam for utilization in industrial processing and turbogeneration of electricity.
For the most part, the body of liquid being heated by solar energy in the prior art devices is contained within a horizontally disposed at least partially light transmissive conduit or in a tower top boiler situated at the focal point of a distributed heliostat field. While it is appreciated that the prior art contemplates solar fueled furnaces comprising a generally vertically disposed conduit for the heating of a body of fluid, generally liquid and more particularly water, and also contemplates the provision of solar fueled furnaces, such as may be used for melting of metals or alloys, having generally vertically disposed solar energy entry windows, which may or may not include a transparent solid windowpane, such apparatuses and methods of utilizing the same have heretofore not generally been suitable for large scale industrial applications.
High purity water for industrial use, potable water and agricultural water are increasingly in short supply. A new fresh water source would be advantageous to all of these uses. Utilizing prior art apparatuses and methods, waste water recovery and purification, including treatment of saline or brackish water, is both expensive and energy intensive. In addition, previously proposed apparatuses and methods for the thermolytic processing of materials, in addition to the aforementioned processes, such as for the calcining of solids, removal of water of crystallization from a solid crystalline matter, energy storage, and food processing either for sterilization or drying, to name a few processes, have not generally been sufficiently efficient to be cost effective so as to be competitive, or potentially competitive, with fossil fueled systems.
In one apparatus disclosed in the prior art an attempt is made to maximize the absorption of solar energy in a directly heated tower top solar furnace, primarily intended for the production of synthesis gas, by directing collected and concentrated solar energy to the light transmissive bottom of a fluid jacket of a solar furnace for the generation of steam that is passed upwardly through a second light transmissive wall for the injection of the steam into an inner chamber of the solar furnace for fluidizing a bed of carbonaceous material and providing the necessary water and heat for carrying forward the reaction for the production of synthesis gas.
As the description of the present invention proceeds, it will be apparent that the present invention is readily distinguishable from the above discussed prior art apparatuses and methods.